EP3793095A1 - Verfahren und system zum optimalen räumlichen multiplexen in drahtloskommunikationssystemen mit mehreren antennen unter verwendung von mu-mimo-techniken - Google Patents

Verfahren und system zum optimalen räumlichen multiplexen in drahtloskommunikationssystemen mit mehreren antennen unter verwendung von mu-mimo-techniken Download PDF

Info

Publication number
EP3793095A1
EP3793095A1 EP19382800.1A EP19382800A EP3793095A1 EP 3793095 A1 EP3793095 A1 EP 3793095A1 EP 19382800 A EP19382800 A EP 19382800A EP 3793095 A1 EP3793095 A1 EP 3793095A1
Authority
EP
European Patent Office
Prior art keywords
antenna elements
transmit
receive antenna
channel condition
condition number
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP19382800.1A
Other languages
English (en)
French (fr)
Inventor
Javier LORCA HERNANDO
Elena Serna Santiago
Juan Francisco ESTEBAN RIVAS
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonica SA
Original Assignee
Telefonica SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonica SA filed Critical Telefonica SA
Priority to EP19382800.1A priority Critical patent/EP3793095A1/de
Priority to PCT/EP2020/075084 priority patent/WO2021052819A1/en
Priority to US17/760,628 priority patent/US11671150B2/en
Priority to BR112022004838A priority patent/BR112022004838A2/pt
Publication of EP3793095A1 publication Critical patent/EP3793095A1/de
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H04B7/0452—Multi-user MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0686—Hybrid systems, i.e. switching and simultaneous transmission
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0686—Hybrid systems, i.e. switching and simultaneous transmission
    • H04B7/0691—Hybrid systems, i.e. switching and simultaneous transmission using subgroups of transmit antennas
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
    • H04B7/0868—Hybrid systems, i.e. switching and combining
    • H04B7/0874—Hybrid systems, i.e. switching and combining using subgroups of receive antennas
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03891—Spatial equalizers
    • H04L25/03898—Spatial equalizers codebook-based design

Definitions

  • the present invention has its application within the telecommunication sector, particularly in wireless communications. More specifically, the present invention proposes a method and system to optimize spatial multiplexing techniques in multi-antenna wireless communications systems (networks), said multi-antenna wireless systems using Multi-User Multiple Input Multiple Output (MU-MIMO) techniques.
  • MU-MIMO Multi-User Multiple Input Multiple Output
  • MIMO techniques are one of the most efficient schemes for increasing the spectral efficiency per user, and per unit area, in wireless networks (for example, in any type of mobile telecommunications networks).
  • MIMO techniques are characterized by the use of multiple antennas for transmission and/or reception at the wireless access point side and usually also at the user (device) side.
  • Multi-User MIMO (MU-MIMO) techniques aim to multiplex several users (user devices) in the spatial domain by simultaneously creating beams that are tailored to the channel state conditions experienced by the users, while also keeping inter-user interference to a minimum; in contrast, Single-User MIMO (SU-MIMO) techniques only deal with a single user device, boosting the single user device throughput by means of spatial multiplexing.
  • MU-MIMO Multi-User MIMO
  • SU-MIMO Single-User MIMO
  • MU-MIMO techniques are limited by the channel matrix characteristics, which in turn depend on the surrounding environment and the degree of correlation between the transmit (at the transmission side) and/or receive (at the reception side) antenna elements (also called radiating elements or, simpler, antennas).
  • a high correlation can occur because of similarities in the antenna responses at the transmit side, the receive side, or both, and can also appear because of insufficient scattering phenomena that hinders excitation of the desired number of spatial layers. The consequence is the inability of the radiating system to exploit the degrees of freedom theoretically present in the wireless channel, thus leading to performance degradation. This is especially harmful when multiplexing users in MU-MIMO, because inter-user interference resulting from the presence of high correlation can be very strong.
  • massive MIMO systems employ a massive number of antennas side (one or two orders of magnitude higher than what would be needed in traditional MIMO systems) at the base station (generally speaking, at the wireless access point).
  • the excess number of antennas leads to some decorrelation of the spatial paths hence improving performance in MU-MIMO.
  • Massive MIMO is characterized by using massive amounts of transmit and receive antennas at the base station side to improve the performance of multi-antenna techniques, namely beamforming (which makes use of multiple independent transceiver chains with full amplitude/phase controls of the signals of each antenna), and spatial multiplexing.
  • DPC Dirty Paper Coding
  • THP Tomlinson-Harashima Precoding
  • Linear precoding techniques are on the contrary simpler to implement, and therefore more popular in Massive MIMO systems that benefit from the presence of large antenna arrays at the base station.
  • the excess antennas enhance the possibilities of linear precoding techniques while still achieving good decorrelation between spatial layers.
  • a high degree of spatial resolution can only be achieved with very large arrays, according to the Nyquist criterion (above 64-128 antenna elements in practical systems).
  • Large arrays give rise to significant front-end complexity which usually limits the use of Massive MIMO to hotspots with heavy traffic and large concentration of simultaneous users.
  • MU-MIMO techniques can be significantly impaired in line of sight (LOS) conditions. Transmit and receive antennas cannot in general be separated much more than half a wavelength if grating lobes are to be avoided. In LOS conditions, and with such inter-antenna spacing, the ability of the antennas to excite spatial layers can be impaired. This happens e.g. in Fixed Wireless Access (FWA) systems operating in millimetre-waves (above 6 GHz), which behave as wireless Point-to-Multipoint systems with good line of sight between the base station and the users. In these systems, the ability of prior art techniques to exploit MU-MIMO is reduced unless smart techniques are devised to select transmit antennas with the lowest possible RF coupling.
  • FWA Fixed Wireless Access
  • base stations can benefit from the presence of several subsectors within a given sector, where subsectors are the result of any partition of a sector of a base station into multiple parts. That is, the coverage area of a base station is spatially divided in sectors, and each of said sectors are divided in subsectors.
  • Subsectors can improve the received signal level by spatially isolating users with the aid of subsector beams, hence achieving additional beamforming gains. That is, wireless systems with the ability to define subsectors can improve the received signal quality.
  • Subsectors in many cases do not provide simultaneous digital control of all the transmit antennas, but just a subset of them, as given by the maximum baseband processing power.
  • the baseband unit may control a maximum of e.g. 8 simultaneous transmit chains, whereas the frontend can comprise three sectors with e.g. 4 antennas per sector, leading to 12 antennas. Finding the optimum association between transmit chains and transmit antennas is therefore key to maximize MU-MIMO performance in this kind of systems.
  • the present invention solves the aforementioned problems and overcomes previously explained state-of-the-art limitations by proposing a method and a system for optimizing the performance of spatial multiplexing techniques in MIMO wireless (communications) systems comprising subsectors, where the presence of significant correlation between antenna elements can impair the performance of MU-MIMO techniques.
  • the proposed embodiments present specific mechanisms to optimize MU-MIMO performance, efficiently exploiting the extra number of transmit and receive antennas.
  • Prior state-of-the-art techniques generally perform a static association of transmit RF (radiofrequency) chains and antennas, in such a way that spatial multiplexing employs of a pre-defined set of antenna elements at the base station.
  • this approach is not the most efficient one when considering the presence of subsectors, because the actual correlation between antenna elements can make transmission more efficient when letting antennas from different subsectors be involved in the transmission towards a set of users in MU-MIMO.
  • the present embodiments proposed can overcome the limitations of prior art techniques by introducing an efficient method to select the optimum combination of transmit antennas as well as the optimum combination of receive antennas in MU-MIMO, that maximize performance.
  • MU-MIMO performance optimization is achieved by means of exhaustive search of the combination of antennas and user devices that yields the lowest possible channel condition number, being simple to implement and represents a good predictor of performance without resorting to detailed capacity calculations.
  • the MU-MIMO wireless systems where the proposed embodiments are applied can be any type of wireless communication system.
  • the wireless system is a cellular communications system for example a 2G, 3G, 4G or 5G mobile communications system or any other type of cellular communications systems.
  • the user devices (equipment) may be mobile telephones, tablets, smartphones, laptops, computers, PCs... (and generally any electronic equipment or device that can be connected to the wireless communication system).
  • the present invention proposes a method to optimize the performance of a MU-MIMO wireless communications system, said wireless communications system comprising at least a base station, with at least one sector having P subsectors with N t transmit antenna elements each, and M user devices (to be served using MU-MIMO wireless techniques) with N r receive antenna elements each, being L the maximum number of transmit antenna elements which the base station can simultaneously control at baseband processing level, characterized in that the method comprises the following steps:
  • step a2 comprises:
  • the optimum combinations of transmit and receive antenna elements obtained may be used by the wireless communications system during a time lower or equal than the coherence time of the channel between the transmit and the receive antenna elements.
  • the wireless system decides not to use MU-MIMO techniques to serve the users devices.
  • the method may be periodically carried out every certain period of time (for example, a period of time is equal to the coherence time of the channels between the transmit and the receive antenna elements).
  • the period of time may depend on the communications protocol used by the wireless system.
  • the optimum combination of L' receive antenna elements obtained may belong to the same user device or to multiple user devices.
  • the MU-MIMO wireless communications system may be for example a 2G, 3G, 4G or 5G mobile communications system or any other type of wireless communications system using MU-MIMO techniques.
  • a MU-MIMO wireless communications system comprising:
  • the electronic device is part of the base station, for example, part of the baseband processing unit of the base station.
  • the electronic device is located in a radio access node of the MU-MIMO wireless communications system.
  • a computer program comprising computer program code means adapted to perform the steps of the described methods, when said program is run on processing means of a network entity of an OFDMA network, said processing means being for example a computer, a digital signal processor, a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a micro-processor, a micro-controller, or any other form of programmable hardware.
  • a computer program comprising instructions, causing a computer executing the program to perform all steps of the described method, when the program is run on a computer.
  • a digital data storage medium is also provided for storing a computer program comprising instructions, causing a computer executing the program to perform all steps of the disclosed methods when the program is run on a computer.
  • FIG. 1 illustrates (without limitation purposes) a wireless system, where the proposed solution is applied according to an embodiment of the invention.
  • the wireless system (or wireless network) comprising at least a base station, serving M (M>1) users (user devices) by means of MU-MIMO techniques (105) (or in other words, the wireless system is a MU-MIMO wireless system).
  • the base station comprising at least one sector (101), the sector comprising P subsectors (102), each subsector having N t transmit antenna elements (103), capable of generating an independent set of wireless beams.
  • Each user device is assumed to be equipped with N r receive antenna elements (104).
  • the base station benefits from full digital control at baseband processing level (106) of up to L simultaneous antenna elements (107) across the P subsectors (that is, the base station has amplitude and phase control of L antenna elements simultaneously) and has full (perfect) a-priori knowledge of the (RF) channels (for example, of the constant channel matrix H) between the PN t transmit antenna elements and the users' MN r antenna elements.
  • L is lower than the total number of transmit antennas at the base station side, PN t .
  • P, N t , N r , M and L are system design features which may have any value depending on the wireless systems where any of the proposed embodiments is applied.
  • the embodiments of the invention are focused in the MU-MIMO operation of the wireless system with a group of user devices, but it is not mandatory that all the user devices served by the wireless system are served using MU-MIMO techniques (pure MU-MIMO wireless system), that is, in some embodiments the wireless system will be a pure MU-MIMO wireless system but in other embodiments, the wireless system may serve other user devices with SU-MIMO techniques. In other words, the wireless system (even the same base station) can serve some user devices as single users using SU-MIMO techniques and serve other user devices using MU-MIMO techniques.
  • the proposed mechanism for association of layers to antenna elements optimizes the actual combination of L transmit antenna elements among the PN t antenna elements contained in the sector, and L' receive antennas among the MN r antenna elements present in the user devices (with L' ⁇ min( L,MN r )), such that MU-MIMO performance is maximized.
  • Figure 1 also illustrates the optimum group of users (109) corresponding to the L' receive antennas selected by the proposed algorithm to maximize MU-MIMO performance, as provided by (108), where users #2, #3 and #4 (in dotted circle) are selected together with a given set of L transmit antenna elements to optimize MU-MIMO performance.
  • FIG. 2 illustrates a scenario where different users are served by different subsectors in a given sector. Partitioning the sector into P subsectors provides an additional gain compared to a more traditional scenario without subsectors, because subsector antennas can point more precisely towards the user locations thus improving the link budget. This obviously requires some mechanism at the base station to identify the best subsector for each user and to associate specific transmit/receive antennas to users depending on the channel characteristics.
  • the aim of the proposed embodiments is to optimize the performance of spatial multiplexing techniques in MU-MIMO wireless systems (that is, in wireless systems using MU-MIMO techniques) or, in other words, to achieve optimum association of antenna elements to spatial layers in MU-MIMO so that cell throughput is maximized.
  • spatial layers are also called streams, or spatial eigen-modes (eigenmodes) of the channels and represent the modes of propagation through which information can be conveyed; layers must always be associated to antennas for their transmission, in a process sometimes called "layer mapping".
  • FIG. 3 illustrates a scenario (a wireless system) where the present embodiments can be applied.
  • M users (users devices) #1, #2, #3 ... # M are served in MU-MIMO by means of a suitable combination of L antenna elements (from the total number of antenna elements, PN t ) across the P subsectors (also called beams) #1, #2, #3 ... # P; being L the maximum number of antenna elements in which (at baseband processing level) the base station can have simultaneous amplitude/phase control in said sector.
  • the MU-MIMO capacity region defined as a region comprising a set of user data rates (the user bit rates or throughput characterizing the connection) with arbitrarily low probability of error.
  • DPC Dirty Paper Coding
  • THP Tomlinson-Harashima Precoding
  • sphere decoding which are simpler to implement but for which no closed-form expressions exist to date for the achievable capacity.
  • the channel condition number generally varies with time and frequency. It is related with the channel rank (the number of singular values not equal to zero of the channel matrix H, it is thus an indicator of how many data streams can be spatially multiplexed on the MIMO channel) but provides better insight on the feasibility of the channel to exhibit multiple spatial layers for wireless transmission. While the channel rank represents a hard limit to the number of spatial layers supported by the channel, the condition number is a real number reflecting the ratio between the magnitudes of the eigenmodes with respectively highest and lowest powers. It states how performance will be degraded as a result of the different relative magnitudes of the eigenmodes: if the condition number is high, the highest eigenmodes will dominate over the weakest ones, and performance will be very sensitive to noise-induced errors. The channel matrix is thus said to be ill-conditioned. In contrast, if the condition number is low, the eigenmodes will have similar magnitudes and performance will be more robust against channel noise.
  • the following steps ensure optimum selection of L transmit antenna elements and L' receive antenna elements ( L' ⁇ min ( MN r , L )).
  • the L transmit antenna elements and L' receive antenna elements that maximizes MU-MIMO performance in a subsector-based MU-MIMO wireless system are selected.
  • the steps will be explained for a MU-MIMO wireless system as the one shown in figures 1 or 3 .
  • Figure 4 illustrates the proposed mechanism in a flow diagram.
  • the last combinations of transmit antenna elements and receive antenna elements ( A i and B j respectively), stored in step 1.5 as the optimum combination of antenna elements will be the outcome of the algorithm. That is, this outcome will be the combination of L transmit antennas and L ' receive antennas (the wireless system will multiplex transmissions towards the L' receive antennas by means of the selected L transmit antennas) that yields the lowest possible channel condition number, and therefore the best expected MU-MIMO performance.
  • said obtained optimum combination of transmit and receive antennas for application of MU-MIMO techniques is kept over a duration lower or equal than the coherence time of the channels (between the PN t transmit antenna elements and the users' MN r antenna elements). And optionally, these steps are repeated after the coherence time of the channel has passed. Likewise, this algorithm can be generally repeated with a periodicity time equal to the coherence time of the channel.
  • the L ' receive antenna elements obtained applying the proposed solution can comprise any combination of antennas, whether belonging to a given user or multiple users, that minimizes the channel condition number.
  • Figure 1 illustrates the optimum group of users (109) corresponding to the L ' receive antennas selected by the proposed algorithm to maximize MU-MIMO performance where users #2, #3 and #4 (in dotted circle) are selected together with a given set of L transmit antenna elements to optimize MU-MIMO performance.
  • the system may decide not to activate MU-MIMO and keep only SU-MIMO operation, depending on the actual implementation.
  • the proposed mechanism can be performed in any electronic device with enough processing capabilities. It may be performed for example by the base station itself (for example, by the baseband processing unit of the base station) or by any other node internal or external to the wireless system (wireless network).
  • the proposed embodiments can be implemented by means of software elements, hardware elements, firmware elements, or any suitable combination of them.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Power Engineering (AREA)
  • Radio Transmission System (AREA)
  • Mobile Radio Communication Systems (AREA)
EP19382800.1A 2019-09-16 2019-09-16 Verfahren und system zum optimalen räumlichen multiplexen in drahtloskommunikationssystemen mit mehreren antennen unter verwendung von mu-mimo-techniken Pending EP3793095A1 (de)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP19382800.1A EP3793095A1 (de) 2019-09-16 2019-09-16 Verfahren und system zum optimalen räumlichen multiplexen in drahtloskommunikationssystemen mit mehreren antennen unter verwendung von mu-mimo-techniken
PCT/EP2020/075084 WO2021052819A1 (en) 2019-09-16 2020-09-08 Method and system for optimal spatial multiplexing in multi-antenna wireless communications systems using mu-mimo techniques
US17/760,628 US11671150B2 (en) 2019-09-16 2020-09-08 Method and system for optimal spatial multiplexing in multi-antenna wireless communications systems using MU-MIMO techniques
BR112022004838A BR112022004838A2 (pt) 2019-09-16 2020-09-08 Método para otimizar o desempenho de um sistema de comunicações sem fio de mu-mimo, sistema de comunicações sem fio de mu-mimo e mídia legível por computador não transitória

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19382800.1A EP3793095A1 (de) 2019-09-16 2019-09-16 Verfahren und system zum optimalen räumlichen multiplexen in drahtloskommunikationssystemen mit mehreren antennen unter verwendung von mu-mimo-techniken

Publications (1)

Publication Number Publication Date
EP3793095A1 true EP3793095A1 (de) 2021-03-17

Family

ID=68069704

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19382800.1A Pending EP3793095A1 (de) 2019-09-16 2019-09-16 Verfahren und system zum optimalen räumlichen multiplexen in drahtloskommunikationssystemen mit mehreren antennen unter verwendung von mu-mimo-techniken

Country Status (4)

Country Link
US (1) US11671150B2 (de)
EP (1) EP3793095A1 (de)
BR (1) BR112022004838A2 (de)
WO (1) WO2021052819A1 (de)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060018288A1 (en) * 2004-01-22 2006-01-26 The Regents Of The University Of California Systems and methods for resource allocation to multiple antenna arrays for maintaining a constant bit rate (CBR) channel
US20070281746A1 (en) * 2006-04-10 2007-12-06 Fujitsu Limited Radio communication method, transmitter, and receiver

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101573072B1 (ko) * 2008-08-27 2015-12-01 엘지전자 주식회사 무선통신 시스템에서 제어정보 전송방법
EP2553830A1 (de) * 2010-04-02 2013-02-06 Interdigital Patent Holdings, Inc. System und verfahren für mehrnutzer-mimo-betrieb in hsdpa
US10499409B2 (en) * 2012-02-02 2019-12-03 Genghiscomm Holdings, LLC Cooperative and parasitic radio access networks

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060018288A1 (en) * 2004-01-22 2006-01-26 The Regents Of The University Of California Systems and methods for resource allocation to multiple antenna arrays for maintaining a constant bit rate (CBR) channel
US20070281746A1 (en) * 2006-04-10 2007-12-06 Fujitsu Limited Radio communication method, transmitter, and receiver

Also Published As

Publication number Publication date
US11671150B2 (en) 2023-06-06
US20220337293A1 (en) 2022-10-20
BR112022004838A2 (pt) 2022-06-07
WO2021052819A1 (en) 2021-03-25

Similar Documents

Publication Publication Date Title
EP3520226B1 (de) System und verfahren zur hierarchischen strahlformung und rangadaption für eine hybride antennenarchitektur
US8204151B2 (en) Methods and apparatus to generate multiple antennas transmit precoding codebook
EP3404843B1 (de) Verfahren zur ermöglichung von analoger und digitaler strahlformung
US8594161B2 (en) Method and system for beamforming in a multiple user multiple input multiple output (MIMO) communication system using a codebook
EP2255459B1 (de) Systeme und verfahren zur verteilten strahlformung auf der basis von träger-zu-verursachten störungen
EP3547558B1 (de) Informationsrückkopplungsverfahren, benutzergerät und netzwerkgerät
US10374676B2 (en) Channel tracking and transmit beamforming with frugal feedback
US10181965B2 (en) Channel estimation method and apparatus in wireless communication system
US8401106B2 (en) Interference rejection combining for multi-user MIMO telecommunications system
US8359042B2 (en) Communication system and method of performing interference control using random beamforming technique
JP2019525637A (ja) プリコーディング行列決定方法およびプリコーディング行列決定装置
KR20120086279A (ko) 다중-셀 협력 통신을 위한 기지국들 및 단말을 포함하는 통신 시스템
EP3163767B1 (de) Verfahren zur meldung eines vorcodierungsmatrixindex für hochfrequenzbandkommunikation in einem drahtloskommunikationssystem und vorrichtung dafür
KR101481391B1 (ko) 채널 상태 정보 피드백 방법 및 그의 시스템
JP2012515483A (ja) Ｍｕ−ｍｉｍｏシステムにおける基地局によって送信されるデータのビームビームフォーミングを行う方法、及びその方法を実行する装置
CN103155624A (zh) 用于lte信道状态信息估计的方法和装置
CN102763447A (zh) 用于采用了多输入多输出(mimo)传输的无线通信系统中的信道状态信息反馈的系统和方法
US8428174B2 (en) Method, pre-coding apparatus and wireless communication system for multiple-input multiple-output collaborative communication
CN104737464A (zh) 在多天线无线通信系统中利用减少的码本找到信道状态信息
CN108288987B (zh) 一种发射分集的方法、终端和基站
US20220321176A1 (en) Approaches for beam measurements
KR20090066198A (ko) 단말의 수신 장치, 기지국의 송신 장치 및 수신 신호 결합 방법
KR20210012080A (ko) 다중 사용자 다중 안테나 통신 시스템의 프리코더 생성 방법 및 프리코더 생성 장치
EP3793097A1 (de) Verfahren und system zum optimalen räumlichen multiplexen in drahtloskommunikationssystemen unter verwendung von su-mimo-techniken
US11671150B2 (en) Method and system for optimal spatial multiplexing in multi-antenna wireless communications systems using MU-MIMO techniques

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210826

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20230301